Coupling & Crosstalk: Disposable Chips?

cups plates forks canstockphoto2604892 250x345Coupling & Crosstalk is my column in the MEPTEC Report. This column appears in the Spring 2014 edition on pages 10-11.

Electronic coupling is the transfer of energy from one circuit or medium to another. Sometimes it is intentional and sometimes not (crosstalk). I hope that this column by mixing technology and general observations is thought provoking and “couples” with your thinking. Most of the time I will stick to technology but occasional crosstalk diversions may deliver a message closer to home.

Disposable Chips?

I’m not a fan of disposable cups and other tableware. Yes, they are convenient and in some cases even economical. However, they are not great substitutes for the “real thing”. Splinters from your chopstick? A broken plastic knife from attempting to cut something? Spork? Need I say more?

Seeking to lessen our family’s environmental impact and set a good example for our children, we practice the green philosophy of reduce-reuse-recycle. Recycle paper, containers, and packaging? Rechargeable batteries? Cloth napkins? Hand-me-downs of children’s clothing to/from friends? All yes plus plenty more. Note the word “practice” which means we are not perfect and can always do better. Do I always leave the house with a reusable water bottle or coffee/tea mug instead of using disposable cups and bottles? No. Should I? Probably.

Last year on the way to the International Technology Roadmap for Semiconductors (ITRS) meeting in Lyon, France I had a revelation on the Rhônexpress light-rail between the airport and downtown. No, it wasn’t my typical jetlagged “where am I?” or “where am I headed?”… What I had noticed was my paper transit ticket purchased from the kiosk had no magnetic strip or printing indicating validity. One side had the basic information about the system. The other side was blank other than a very small dot matrix printed serial or control number. Did the vending machine malfunction and neglect to print my purchased fare on the card?

Being very tired and figuring I could be just another non-French speaking tourist if need be, I boarded the train. While waiting for the conductor, I discovered a telltale lump approximately 1 mm in diameter. Watching the conductor tap the cards to his handheld terminal and holding the card up to the light confirmed my suspicions. These tickets have embedded radio-frequency identification (RFID) circuits consisting of an antenna and an integrated circuit (IC).

The use of RFID “tags” was not exactly a revelation since I’ve seen them for a number of years in everything from credit cards to library books. I’ve had RFID chips in my credit cards since American Express introduced Express Pay in 2005. Our local library installed RFID checkout system several years ago. And I’m no stranger to using “reloadable” RFID cards for transit systems. I’ve got Suica, Oyster, Clipper, Octopus, and Shanghai Public Transit cards sitting in my travel box. (Bonus points if you can name the matching cities. Shanghai Metro marketing gets no points for naming creativity.)

The revelation is that the RFID tags especially the silicon IC have become sufficiently inexpensive to use them for one-time disposable applications.

In the other cases the useful life is far longer – one or two years for credit cards, several years for transit passes, and years if not a decade or more for library books. And these are definitely higher value and multi-use applications.

Until the recent Target credit card data theft fiasco, US banks and merchants have resisted the costs to implement the Europay Mastercard Visa (EMV) “smart card” system. The EMV chip card has been proven to reduce fraud across Europe and around the globe. In light of the recent fraudulent transaction and lost business costs, those smart cards with encryption chips have since become “essential”. Previously the inconvenience of transitioning the United States (US) was greater than the perceived value. Target has pledged to spend $100 M to accelerate their deployment in their nearly 1,800 stores and all of their proprietary charge & debit cards within the next year.

Beyond RFID ICs it is clear that more of our electronics have or will shortly become disposable. There are electronic greeting cards that play pre-recorded tunes or allow the giver to personalize their message. Hopefully the batteries last long enough to play the message more than a handful of times. Do you too have a collection of USB “memory sticks” from conferences and suppliers in your desk? Certainly the older ones with as little as 128 MB capacity are basically disposable.

Mobile phones exceeded 100% penetration at the end of 2012 –marketing speak for having more active mobile phone accounts than the world’s population (~7 B). And many mobile carriers are shortening phone replacement cycles from two years. Clearly some mobile phones are becoming disposable. I’ve been lucky enough to resell (reuse) some of my prior generation high-end smartphones when I’ve upgraded. But what happens to feature phones costing less than $25? I have a few of those in my travel box too…

Proteus Digital Health even has an ingestible semiconductor based sensor. The sensor is encapsulated in individual pills and powered by stomach acid. Their system can then report the time of ingestion and specific serial number for each dose of medicine. It is not clear how much of chip is broken down and absorbed versus what remains to be “passed”. Proteus simply says the sensor moves “through the body in the normal process of digestion”. I’m not certain I want to try to recycle what remains. Clearly a single-use application that is disposable.

Sometimes we can reuse our electronics by moving them to new users or uses. With current trends of increasing number of “must have” electronics and the market pressure of Moore’s Law continuing to decrease the price of semiconductors, is it is very unlikely that the world will reduce its consumption. What about recycling? Even though some in-process scrapped materials  (such as full silicon wafers) can be recycled or reclaimed, significant recycling of finished semiconductors is difficult and inefficient. Yes, miniscule amounts of gold can be extracted. However gold use is declining rapidly with the transition to lower cost copper wire bonds and flip-chip packaging. At the same time an even greater set of exotic materials from all across the periodic table including several new III-V materials are being used to build semiconductors. When is the last time you purchased hafnium, let alone recycled it?

The Internet of Things (IoT) and sensor applications being described by the TSensors Roadmap require a few fundamental technologies. In order to enable applications with massive numbers of sensors (millions and above), sensor units will require both wireless connectivity and internal power – either long lasting batteries and/or self-generation. Wireless communication is needed since with these quantities of sensors it will be neither practical nor economical to “hard wire” them. By using the appropriate sensors and low power electronics, the devices will last the needed five to ten years or more without maintenance to replace the batteries.

It is clear to many in the TSensors community that ultimately the price per microelectromechanical system (MEMS) sensing element needs to be on the order of $1 to enable the economics of these applications. TSensors applications are the ultimate high volume application for disposable electronics. We will need to determine what to do with a million, let alone a trillion or more, sensor units when they are no longer useful. Recycling needs to be added alongside cost, power, and wireless requirements to enable this exciting new technology!

As always, I look forward to hearing your comments directly. Please don’t hesitate to contact me to discuss your thoughts.


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